PT - JOURNAL ARTICLE AU - GIRDLER, RONALD WILLIAM TI - THE RELATIONSHIP OF THE RED SEA TO THE EAST AFRICAN RIFT SYSTEM AID - 10.1144/gsjgs.114.1.0079 DP - 1958 Nov 01 TA - Quarterly Journal of the Geological Society PG - 79--105 VI - 114 IP - 1-4 4099 - http://jgs.lyellcollection.org/content/114/1-4/79.short 4100 - http://jgs.lyellcollection.org/content/114/1-4/79.full SO - Quarterly Journal of the Geological Society1958 Nov 01; 114 AB - The Red Sea is characterized by positive gravity anomalies along its centre, whereas the East African Rift Valleys have negative anomalies. The Red Sea trough is more than 200 miles wide but the gravity maximum appears to be associated with a deep trough (about 30 to 40 miles wide), the anomalies on each side being small. A table is given of gravity data for the Red Sea area, and the values have been revised so that they are directly comparable. To assist in the interpretation of these data a brief review is given of the dimensions of the Rift Valleys, and the general geological structure and history of the area. The interpretation of negative anomalies over the East African Rift Valleys is discussed and the Red Sea anomalies are described and contrasted with those of the East African Rifts. The gravity maximum is interpreted as being due to a large basic mass intruded through the down-faulted basement rocks. It is suggested that the formation of the fault trough which the Red Sea occupies and the deep, relatively narrow axial trough is connected with the intrusion and a possible mechanism is given.